/* ========== 设计变量 ========== */
:root {
  --color-bg: #fafafa;
  --color-surface: #ffffff;
  --color-text: #1a1a2e;
  --color-text-secondary: #5c5c6e;
  --color-border: #e6e6ee;
  --color-accent: #4f6ef7;
  --color-accent-dark: #3b57d9;
  --color-demo-bg: #fff4e0;
  --color-demo-text: #8a5a00;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(26, 26, 46, 0.06), 0 4px 14px rgba(26, 26, 46, 0.05);
  --max-width: 1080px;
  --font-sans: system-ui, -apple-system, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
}

/* ========== 基础 ========== */
*, *::before, *::after { box-sizing: border-box; }

html { font-size: 16px; }

body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; display: block; }

a { color: var(--color-accent); text-decoration: none; }
a:hover { text-decoration: underline; }

code {
  background: #eef0f7;
  padding: 0.1em 0.35em;
  border-radius: 4px;
  font-size: 0.88em;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* ========== 导航 ========== */
.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  min-height: 60px;
}

.brand {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--color-text);
}
.brand:hover { text-decoration: none; }
.brand-accent { color: var(--color-accent); }

.nav-links {
  display: flex;
  gap: 0.25rem;
  list-style: none;
  margin: 0;
  padding: 0;
  flex-wrap: wrap;
}

.nav-link {
  display: block;
  padding: 0.45rem 0.9rem;
  border-radius: 8px;
  color: var(--color-text-secondary);
  font-size: 0.95rem;
}
.nav-link:hover {
  color: var(--color-text);
  background: #f0f1f7;
  text-decoration: none;
}
.nav-link.active {
  color: var(--color-accent);
  font-weight: 600;
}

/* ========== 首页 Hero ========== */
.hero {
  padding: 4.5rem 1.25rem 3rem;
}

.hero-title {
  font-size: clamp(1.9rem, 4.5vw, 2.9rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin: 0 0 1rem;
}

.hero-sub {
  font-size: 1.08rem;
  color: var(--color-text-secondary);
  max-width: 42rem;
  margin: 0 0 1.8rem;
}

.hero-actions { display: flex; gap: 0.75rem; flex-wrap: wrap; }

.btn {
  display: inline-block;
  padding: 0.6rem 1.4rem;
  border-radius: 9px;
  font-size: 0.95rem;
  font-weight: 600;
  transition: background 0.15s ease;
}
.btn:hover { text-decoration: none; }

.btn-primary { background: var(--color-accent); color: #fff; }
.btn-primary:hover { background: var(--color-accent-dark); }

.btn-ghost {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border);
}
.btn-ghost:hover { background: #f0f1f7; }

/* ========== 区块 ========== */
.section { padding: 1.75rem 1.25rem; }

.section-narrow {
  max-width: 46rem;
  margin: 0 auto;
  padding: 2.5rem 1.25rem;
}

.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.section-title {
  font-size: 1.3rem;
  font-weight: 700;
  margin: 0 0 1.1rem;
}

.section-more { font-size: 0.92rem; white-space: nowrap; }

.page-title {
  font-size: 1.9rem;
  font-weight: 800;
  margin: 0 0 0.6rem;
  letter-spacing: -0.01em;
}

.page-sub {
  color: var(--color-text-secondary);
  margin: 0 0 1.6rem;
}

/* ========== 技能标签 ========== */
.skill-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  list-style: none;
  padding: 0;
  margin: 0;
}

.skill-chip {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  padding: 0.35rem 0.95rem;
  font-size: 0.9rem;
  color: var(--color-text-secondary);
}

/* ========== 项目卡片 ========== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(290px, 1fr));
  gap: 1.4rem;
}

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  color: var(--color-text);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  display: flex;
  flex-direction: column;
}
.card:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 22px rgba(26, 26, 46, 0.1);
  text-decoration: none;
}

.card-cover {
  position: relative;
  aspect-ratio: 16 / 9;
  background: #eef0f7;
  overflow: hidden;
}
.card-cover img { width: 100%; height: 100%; object-fit: cover; }

.badge-demo {
  position: absolute;
  top: 0.6rem;
  right: 0.6rem;
  background: var(--color-demo-bg);
  color: var(--color-demo-text);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.15rem 0.6rem;
  border-radius: 999px;
  border: 1px solid #f0dcae;
}

.badge-inline {
  position: static;
  display: inline-block;
  vertical-align: middle;
  margin-left: 0.6rem;
  font-size: 0.8rem;
}

.card-body { padding: 1rem 1.15rem 1.15rem; flex: 1; }

.card-title { margin: 0 0 0.4rem; font-size: 1.08rem; font-weight: 700; }

.card-desc {
  margin: 0 0 0.75rem;
  font-size: 0.92rem;
  color: var(--color-text-secondary);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-meta {
  font-size: 0.82rem;
  color: var(--color-text-secondary);
  display: flex;
  gap: 0.8rem;
}

/* ========== 项目详情 ========== */
.back-link { margin: 0 0 1rem; font-size: 0.92rem; }

.project-head { margin-bottom: 1.4rem; }

.project-meta {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-wrap: wrap;
  color: var(--color-text-secondary);
  font-size: 0.88rem;
}

.tag {
  background: #eef0f7;
  border-radius: 999px;
  padding: 0.1rem 0.7rem;
  font-size: 0.8rem;
}

.project-cover {
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  margin-bottom: 1.6rem;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background: #eef0f7;
}

.project-tech { margin-bottom: 1.6rem; }

.project-link { margin-top: 2rem; }

/* ========== 正文排版（Markdown 渲染） ========== */
.prose h2 {
  font-size: 1.25rem;
  margin: 2rem 0 0.7rem;
  padding-bottom: 0.35rem;
  border-bottom: 1px solid var(--color-border);
}

.prose p, .prose li { color: #33334a; }

.prose ul { padding-left: 1.4rem; }

/* ========== 联系 / 404 / 页脚 ========== */
.contact-section { padding-bottom: 3.5rem; }
.contact-text { margin: 0.35rem 0; color: var(--color-text-secondary); }

.not-found { text-align: center; padding-top: 5rem; padding-bottom: 5rem; }

.site-footer {
  border-top: 1px solid var(--color-border);
  background: var(--color-surface);
  margin-top: 2rem;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding-top: 1.4rem;
  padding-bottom: 1.4rem;
  font-size: 0.88rem;
  color: var(--color-text-secondary);
}
.footer-inner p { margin: 0; }

/* ========== 移动端 ========== */
@media (max-width: 640px) {
  .hero { padding: 3rem 1.25rem 2.2rem; }
  .nav { padding-top: 0.5rem; padding-bottom: 0.5rem; }
  .card-grid { grid-template-columns: 1fr; }
  .footer-inner { flex-direction: column; }
}